1. Field of the Invention
This invention relates to integrated circuit circuits and more particularly to thermal monitoring of integrated circuits.
2. Description of the Related Art
Integrated circuits have typically measured temperature at a single point on an integrated circuit die, often using an analog (diode) structure. That one measured temperature was considered to be representative of the entire die area. However, in integrated circuits such as microprocessors the geometries utilized in the integrated circuit have decreased, speed has increased and power utilization has increased. The area around regions that are densely populated with switching transistors tends to be much hotter than the average die temperature resulting in a thermal gradient across the die. In fact areas of the die can be 25° C. hotter than other areas of the die in 130 nm technology at 90 W. The thermal gradient will be even greater as geometries continue to decrease and power densities increase.
If the temperature of an integrated circuit, or a portion of an integrated circuit, rises above a certain maximum temperature, damage can result.